Toothed bar structure for peg tooth harrow

ABSTRACT

1,091,612. Agricultural implements. INTERNATIONAL HARVESTER CO. Nov. 15, 1965 [Dec. 2, 1964], No. 48400/65. Heading A1B. Harrow teeth 16 are fixed to tubular cross-bars 11 by driving the teeth 16 through the walls of the tube so that the metal of the tube ruptured by the pointed end of the teeth closely surrounds and grips the teeth. An annular die may be placed beneath the bar to control the shape of the ruptured metal that projects outwardly of the bar around the shank of the teeth. To increase the locking engagement of the teeth with the bars, the metal of the teeth and bars is caused to age and rust particularly in the areas of the interlock.

1969 J. MORKOSKI 3,463,242

TOOTHED BAR STRUCTURE FOR PEG TOOTH HARROW Original Filed Dec. 2, 1964INVENTOR.

TT/orffas Ki United States Patent 3,463,242 TOOTHED BAR STRUCTURE FORPEG TOOTH HARROW James Morkoski, Clarendon Hills, Ill., assignor toInternational Harvester Company, a corporation of Delaware Originalapplication Dec. 2, 1964, Ser. No. 415,539, now Patent No. 3,325,879,dated June 20, 1967. Divided and this application Sept. 2, 1966, Ser.No. 630,145 Int. Cl. A01b 23/02, 15/02, 15/12 US. Cl. 172-713 3 ClaimsABSTRACT OF THE DISCLOSURE A toothed bar for a peg tooth harrowcomprising a tubular bar with transversely aligned openings defined byflanges ruptured from the wall of the bar, each flange taperingdownwardly and being of generally frusto-conical form and sphincterallyembarcing a tooth extending therethrough.

This invention relates to agricultural apparatus and more specificallyto a peg tooth harrow and to a method of making the same, and is adivision of my application Ser. No. 415,539, filed Dec. 2, 1964, and nowPatent No. 3,325,879.

One of the problems inherent in current peg tooth harrow constructionsis in the fastening of the teeth of the harrow to the supporting barstructure. These connections in general are either bolted or weldedtypes. The bolted connections entail extensive manual handling inassembling and in the manufacturing of the respective parts whereby thecosts are exceedingly prohibitive. In the welding attachment the rangeof metals or compositions to be used is limited so as to obtain goodweldments and furthermore the welding requires a highly skilled operatorto insure a good weld between the hard teeth and the more malleablesupport bar. The welding, of course, causes structural deterioration ofthe parts because of the heating necessary to effect the welding.

A general object of the invention is to provide a novel securement ofsimple and effective strength between the support bar and the respectiveteeth.

A further object of the invention is to provide a novel securementbetween a tooth bar and the teeth which comprises punching the teeththrough the support bar in such manner as to rupture the metal of thesupport bar to effect a tight wedging engagement therebetween withoutthe necessity of welding or any other securement.

A still further object of the invention is to provide an improved harrowwherein the support bar is in the nature of a cylindrical tube, the tubeitself serving as a pivot to the frame of the harrow.

A still further object of the invention is to provide a novel method ofsecuring a harrow tooth to the support bar which comprises using thesharpened or pointed tooth as a punch for penetrating the bar wherebyrupturing the metal of the bar and by the wedging effect obtainedestablishing effective securement therebetween.

These and other objects and advantages inherent in and encompassed bythe invention will become more readily apparent from the specificationand the drawings wherein:

FIGURE 1 is a fragmentary perspective view of a harrow incorporating theinvention;

FIGURE 2 is an enlarged longitudinal sectional view of a portion of atooth bar incorporating the invention the view being taken substantiallyon line 22 of FIG- URE 1;

FIGURE 3 is a cross-sectional view of the bar at the tooth connectiontaken substantially on line 3-3 of FIG- URE 2; and

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FIGURE 4 is a horizontal section taken substantially on line 3--3 ofFIGURE 2.

Describing the invention in detail there is shown a peg tooth harrowgenerally designated 2 which comprises a framework generally indicatedas 4 which includes a pair of channel shaped longitudinally extendingside rails'5, 5.

Each side rail 5 comprises a vertical web 6 and top and bottom flanges 7and 8. The vertical web 6 is apertured at selective intervalslongitudinally thereof to provide pivot openings 9. Correspondingopenings 9 in the side rail members 5 receive therethrough opposite endportion 10 of a pivot and tooth support bar generally designated 11. Thebar 11 is a tubular structure or cylindrical tube having a wall 11' andan internal bore 12. Each bar 11 is secured at each end to theassociated side beam member 5 by means of cotter keys or other securingmeans 15, 15 which are passed through suitable apertures in the bar atopposite sides of the respective wall 6. Thus, the bar is restrictedagainst axial or endwise movement with respect to the frame members 5,5. The wall thickness may be of any desired dimension and thecomposition of material may be as desired provided it is softer than thetooth 16 and permits penetration by the tooth.

One of the features of the present invention is in the securement of therake teeth or pegs 16 to the respective bars 11. This securement iseffected by placing the bar or tube in a suitable guide or support anddriving the teeth 16 therethrough as by a punch press, which, if desiredmay be automatic. In other words the bar may be moved and the teethdriven through the bar in an automated press.

It will be seen that the teeth 16 are generally diamondshaped or squarein cross-section and have a lower pointed end 18 which is adapted topierce the bar, the tooth being driven through the tube 11 with suchforce as to cause the bar to become ruptured to provide openings 20, 21in diametrically opposite sides of the bar, namely the upper and lowersides. It will be observed that in the punching operation, the metalwhich normally bridges the openings 20 and 21 is caused to elongateuntil it ruptures whereupon it provides a downwardly coned wedge lockingstructure or securing means 24 in the upper portion of the tube, saidlocking means 24 entering into the bore 12 of the tube. The penetrationof the tooth 16 also develops the aperture 21 and elongates the metal ofthis area into a downwardly coned wedge locking structure 25. It will beunderstood that this punching operation is performed on cold metal, thatis, both the tooth 16 and the tube 11 are cold when the punchingoperation is performed. Of course, it will be appreciated as the metalupon being punched is stretched in rupturing there is a momentaryheating of the apertured areas with consequent at least some expansionof the opening and also reduction of the coefficient of friction.Immediately thereafter the metal cools and contracts and that togetherwith the tension developed in the metal since it is not free flowingprovides a spincterlike clamping action by the conical portions 24 and25 against the tooth 16. Furthermore, it will be realized that the loweredges 26 and 27 are jagged and they have a tendency to gall into thesides of the penetrating tooth 16.

In addition to the cone interlock there is a structural interlockbecause of the shape of the tooth which is substantially diamond-shapedin cross-section having sides 29, 30, 31 and 32. Thus, thefrusto-conical or pyramidal shapes of the portions 24 and 25 haveportions 33, 34, 35 and 36 which complement and oppose the respectivesides 29 through 32. Thus, the tooth is interlocked against relativerotation about its longitudinal axis with respect to the tooth bar.Furthermore, the cross-section of the wedge portions 22, 25 contours themetal so as to provide rigidity in the direction circumferentially ofthe axis of the bar 11 that is along transaxial planes and in uselongitudinally of the tooth, that is generally vertically.

The foregoing structures have been actually made and in such structuresit has been determined that loads in excess of 2100 lbs. have beenexerted on the tooth to withdraw it from the support bar by pulling onthe upper end and 1500 lbs. were required to push the tooth on the bluntend to effect separation and withdrawal from the tooth from the bar.

As an example to the structure axially made the bar 11 was a round lightwall structural pipe 1% in diameter with a wall thickness of 20% lighterthan standard, that is 110 inches. Standard 1%" pipe is defined asASTM-A- 120-62T schedule 40. The peg tooth is preferably of steelidentified as 7-1044.

It will be realized that a novel method has been developed for attachingthe peg teeth to the tooth bar which comprises providing a tubular toothbar or one with spaced transversely aligned portions and then driving atooth through the metal of these portions to rupture the portions and toeflect a mechanical interlock between these portions and the tooth. Inaddition to the physical distortion of the tooth bar in order to improvethe interlock the metal, which is of a steel or ferrous metal, is causedto age and to rust particularly in the areas of the interlock and thusthe rusting of the parts tends to form a mechanical bond and to increasethe coeflicient of friction between the parts to further add to theinterlock at the joints. A die D, shown in phantom, may be provided tocontrol flow of the flanges of the lower interlock 25.

It will be further apparent that the cold punching by the use of theteeth themselves effects a contour of the metal around the respectiveopenings such that the tooth bar in such areas is actually rigidified.The flanges 33 through 36 as well as the similar flanges on the lowerportion 25 produce a vertical columnar effect whereby the bar is notweakened in these areas such as would normally promote early fatiguefailures with jagged openings.

What is claimed is:

1. The combination of a support bar having a tubular wall section withtransversely aligned openings therein, a tooth extending transversely ofthe bar through said openings, and integral flange means on said wallsection about each opening having a sphincteral engagement with thetooth and wherein said flange means extends axially of the tooth, theflange means about one opening projecting internally of the tube and theflange means about the other opening projecting externally of the tube,said flange means being generally frusto-conical and tapering downwardlytoward the tooth.

2. The invention according to claim 1 and said flange means comprising aplurality of jagged points penetrating into the sides of said tooth.

3. The invention according to claim 1 and said tooth being polysided andsaid flange means complementally conforming to the shape of the tooth.

References Cited UNITED STATES PATENTS 265,084 9/1882 Howard 172-713522,086 6/1894 Porteous 1727l3 910,541 1/1909 Horner 172-635 1,093,9144/1914 Close 29160 3,043,377 7/1962 Urben 172-635X ROBERT E. BAGWILL,Primary Examiner ALAN E. KOPECKI, Assistant Examiner US. Cl. X.R.

